Problem conclusion

In BranchManager & ProxyBranchImpl, 2xx/6xx response is now
treated as the best reponse (without sending it as branch
reponse to the application).
In addition in order to enable the fix, the following custom
property should be added in the administrative console (like
any other SIP Container custom property) and set to 'true':
'treat.2xx.6xx.as.best.response'.
The default value of this property is 'false'.
The fix for this APAR is currently targeted for inclusion in
fix packs 8.0.0.7 and 8.5.0.2. Please refer to the
Recommended Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980